Vitamin B12: what are its benefits for the skin?

Employed in both cosmetic formulations and dermatological creams, the main benefit of vitamin B12 in topical application is its ability to soothe the skin. Studies in vitro have indeed shown that this active ingredient can reduce the production of pro-inflammatory cytokines. As a reminder, cytokines are proteins involved in intercellular communication but also in the onset of skin irritations (redness, itching…). They are primarily produced by T lymphocytes, cells of the immune system.

It is also thought that vitamin B12 has an inhibitory effect on nitric oxide (NO) synthesis, a molecule involved in the pathogenesis of eczema and of psoriasis. This compound is produced by the enzyme nitric oxide synthase (NOS), whose overactivity is implicated in both of the aforementioned skin disorders. Indeed, an excess of nitric oxide in skin cells stimulates keratinocyte differentiation and promotes dilation of blood vessels, a process that leads to redness and edema. These anti-inflammatory properties of vitamin B12, first observed in vitro, were later confirmed in clinical trials. Some of these are presented below.

The soothing properties of vitamin B12 make it a valuable asset for compromised or irritated skin.

In addition to its anti-inflammatory effects, vitamin B12 has antioxidant activity that enables it to counteract damage caused by free radicals. Generated following prolonged exposure to UV radiation, pollution, or tobacco, these reactive molecules contribute to structural alterations of proteins and lipid membranes and damage DNA, which compromises skin integrity and can lead to pigmentation spots while accelerating the onset of wrinkles and skin sagging.

Studies in vitro have shown that vitamin B12, thanks to its chemical structure rich in double bonds, can stabilize free radicals by donating an electron. Moreover, this active ingredient works by activating certain molecules that play a key role in maintaining the cellular redox potential, such as glutathione. These effects enable vitamin B12 to protect the skin from oxidative stress and help to prevent skin aging.

Moreover, some studies in vitro have demonstrated that vitamin B12 may benefit the skin regeneration process. It appears, in fact, that this vitamin can stimulate the proliferation of fibroblasts, the cells responsible for producing collagen and elastin. These structural proteins are vital to the skin, especially during wound healing, when a wound closes.

Furthermore, according to these studies in vitro, vitamin B12 appears to be heavily involved in angiogenesis and could therefore contribute to the formation of granulation tissue, a transient, vessel- and cell-rich tissue whose production corresponds to one of the important phases of the wound healing. In light of these initial findings, we can cautiously hypothesize that vitamin B12 may play a regenerative role in the skin.

A study specifically evaluated an innovative dressing composed of a polycaprolactone/gelatin nanofibrous matrix enriched with vitamin B12. The researchers first confirmed that adding vitamin B12 did not alter the material’s physical properties (mechanical strength, water absorption, permeability, hydrophobicity). In a rat skin wound model, this dressing showed a marked improvement in wound healing. Histological analysis also revealed a greater epithelial thickness with the enriched formulation, indicating enhanced healing.

In light of these positive results, it would be valuable for researchers to explore the vitamin’s wound-healing properties in future clinical trials.

The vitamin B12 is sometimes considered a potential hydrating active ingredient. Some hypotheses suggest it might enhance the skin’s water-retention capacity by limiting certain inflammatory processes that compromise the skin barrier. This indirect effect on hydration further underscores its potential benefit in eczema, where the skin barrier is weakened, and transepidermal water loss is often increased.

In this context, a study evaluated the efficacy of a topical gel containing 0.07% adenosylcobalamin, one of the active forms of vitamin B12, in 22 children aged 2 to 12 years with atopic dermatitis. Over eight weeks, participants applied the gel twice daily to the affected areas. The results show a continuous and significant improvement: the SCORAD score decreased from 21.95 at baseline to 13.92 (a 36.58% reduction) after four weeks, then to 6.56 after eight weeks (a 70.11% reduction). Skin hydration, for its part, nearly tripled, while transepidermal water loss markedly decreased.

However, these results should be interpreted with caution. The study did not include a control group using the same hydrating base without vitamin B12, which precludes formally isolating the effect of vitamin B12 itself.

Vitamin B12 plays a role in skin pigmentation. Several studies show that a vitamin B12 deficiency is often accompanied by hyperpigmentation, related to excessive stimulation of melanogenesis. A recent study reproduced a B12-deficient state in the laboratory by exposing melanocytes to a specific vitamin B12 antagonist. These cells then exhibited a marked increase in melanin production and tyrosinase activity, on the order of 130%. This overactivation was accompanied by significant oxidative stress, which disrupts melanocyte homeostasis.

Correcting a vitamin B12 deficiency may help attenuate hyperpigmentation when the deficiency is the cause.

A clinical case illustrates this well: a 49-year-old man exhibited marked hyperpigmentation of the skin and mucous membranes due to malabsorption following a gastrectomy. Laboratory tests revealed a severe vitamin B12 deficiency, and histological examinations showed an accumulation of melanin in the basal layer, as well as numerous melanosomes in melanocytes and keratinocytes, confirming pigment overproduction. After one month of daily vitamin B12 supplementation (0.5 mg per day by injection), his blood level normalized and the hyperpigmentation gradually regressed.

This close connection between vitamin B12 levels and the regulation of melanogenesis sometimes leads to the assumption that topical application of vitamin B12 could likewise exert a depigmenting effect.

The idea is based on a simple rationale: if a deficiency increases melanin synthesis, then a local supply could, in theory, help rebalance melanocyte activity. However, this remains only a hypothesis at present. To date, no study has demonstrated that a topical application of vitamin B12 can lighten the skin or reduce hyperpigmentation. The available data concern only systemic supplementation in cases of confirmed deficiency. It would nevertheless be worthwhile for clinical trials to explore this topic.

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